Method and apparatus for the removal of waste in



Apnl 14, 1964 uu|:)- 3,128,929 METHOD AND APPARATUS FOR THE REMOVAL OF WASTE IN THE PREPARATION OF CONTAINER BLANKS OF SHEET FORMED MATERIAL Filed May 22, 1962 F/G./. 2 3-5. 4 gm IN vs Nrq 5W Mwi;

United States Patent 3,128,929 METHGE) AND APPARATUS FUR THE RE- MDVAL 9F WASTE EN THE PREPARATION 0F CONTAENER BLANKS 0F SHEET FQRMED MATERTAL Gunnm Rand, Sarpsborg, Norway Filed May 22, 1962, Ser. No. 196,368 Chums priority, application Norway May 26, 1961 2 Ciahns. (Cl. 225-103) The present invention relates to a method and apparatus for the removal of such waste or stamp snips (punchings) which necessarily are formed in the preparation of blanks for containers and the like made of sheet formed material, such as thick paper, cardboard, plastic etc. In the preparation of such material into blanks suitable to be folded into container shape, the sheet material is provided with stamped weakening lines conforming with the contour of each blank. Hereby waste areas are formed along the edges of the sheet and such areas, the so called stamp snips, must be detached along the weakening lines prior to further treatment of the blanks, such as printing, folding etc. The removal of the waste is efiected with the sheets placed in a stack and is usually performed by means of strokes with a hammer or by means of a pressure air tool. This procedure is time consuming and often endangers the blanks to damage or wreckage, due to the fact that the sheets may be inaccurately and unevenly stacked when coming from the stamping machine.

It is the purpose of the present invention to bring about a labour and material saving, a saving which amounts to of the time required for the operation and a loss of material which is reduced to nil. According to the invention, the waste areas are removed by means of a tool comprising a rotary disc provided with teeth or similar projections, and adapted to rotate with high velocity, so that the waste areas or stamp snips, when contacted by the teeth are torn off the edges of the sheets along the weakening lines. When the tool is moved downwardly along a stack of cardboard sheets, the snips are torn off in succession and are removed from the stack in a steady stream. For the purpose of facilitating this operation, the waste areas are divided into portions of suitable width by means of additional weakening lines extending from the edge lines proper to the sheet edge, at an angle to the edge lines provided in the same operation as the main weakening lines of the container blank.

The invention is to be more fully described with reference to the accompanying drawings, in which FIGURE 1 is a plan view of a cardboard sheet including six container blanks.

FIGURE 2 is a side view of the tool.

FIGURE 3 is a perspective view of the tool in operation on a stack of sheets.

A cardboard sheet is provided as by stamping with completely out lines and with weakening lines indicated as extending corresponding to the contours of the six container blanks A to F and the waste areas 1 are, by means of weakening lines 2 divided into portions of reduced width, such as the corner portion 3 situated between the cuts 2 and 2 and the intermediate portion 4 situated between the cuts 2 and 2 as well as the corner portion 5 situated between the cuts 2 and 2 For the purpose of removing the waste portions so enumerated, the tool is positioned at 6 6 and 6 respectively.

The rotatable tool is shown in FIGURE 2 and com- 3,128,929 r assures Apr. 14, 1964 prises a rotatable disc 3, which is mounted on a shaft 9 which, through bevel gears (not shown) is driven through a flexible shaft it from a small motor (not shown) of adjustable velocity. A number of disc revolutions of 6390 per minute, has proved very suitable for the present purpose. The shaft 9 is mounted in bearings situated in the projections SLOWII to either side of the handle 11 and is surmounted by a shield 12, covering the disc The top front edge 13 of the shield 12 is overturned, as shown, so as to be adapted to serve as a guide along the side face of the stack when the tool is carried downwardly the same, to the eiiect that the cardboard is not damaged. The lower edge of the shield 12 is provided with a guide plate 15 which serves to direct the flow of pulled off stamp ships 14 downwardly, as shown in FIGURE 3. In FIGURE 3, the stamp snips have been removed along the outer sides of the blanks C and E, and the tool is operating to remove the snips 14 between the blanks E and F. When all waste is removed in this manner and the container blanks of each sheet are divided, the intermediate portions 7 usually are readily removable, but may also be removed by means of the same tool, if required.

The rotatable disc is shown in FIGURE 2 in the embodiment which has proved to be the most effective. In this case, the disc is provided with six teeth which, when the disc is rotating are rapidly tearing off the stamp snips by combined stroke and friction action. The width of the disc would usually be about 5 mm. The top portion of each tooth may be transversely or crosswisely corrugated, or may be treated in other manner for the purpose of increasing the friction of the contact surfaces against the cardboard. It is also possible to use a disc of circular or waveformed circumference, and the disc may possibly be made, wholly or in part, of materials having a high frictional coefi'icient. Further variations are also possible within the scope of the claims.

I claim:

1. A tool for removing waste material portions situated along the edges of sheet material such as cardboard as defined by weakening lines in the sheet material where the sheets are vertically stacked with the waste portions in substantial alignment comprising in combination, means sequentially presenting a series of tooth-like projections cyclically at a vertically positionable working plane passing through the waste portions of each sheet in said stack, structural contour on the projection to produce at the working plane a vertical striking action combined with a laterally frictional motion substantially in the Working plane to strike the waste material portions and thereafter frictionally tear them laterally in the plane of the sheets, said projections being spaced with respect to the cyclically presenting means so that each tooth sequentially engages a waste portion on a successive one of the sheets in said stack, and guide means on the tool shaped for positioning the projections at a position relative to the edges of the sheets in the stack and directing the flow of separated waste portions along a defined path.

2. A tool as defined in claim 1, wherein the projections comprise a series of teeth about a rotatable disc.

References Cited in the file of this patent Marshall Oct. 23, 1962. 

1. A TOOL FOR REMOVING WASTE MATERIAL PORTIONS SITUATED ALONG THE EDGES OF SHEET MATERIAL SUCH AS CARDBOARD AS DEFINED BY WEAKENING LINES IN THE SHEET MATERIAL WHERE THE SHEETS ARE VERTICALLY STACKED WITH THE WASTE PORTIONS IN SUBSTANTIAL ALIGNMENT COMPRISING IN COMBINATION, MEANS SEQUENTIALLY PRESENTING A SERIES OF TOOTH-LIKE PROJECTIONS CYCLICALLY AT A VERTICALLY POSITIONABLE WORKING PLANE PASSING THROUGH THE WASTE PORTIONS OF EACH SHEET IN SAID STACK, STRUCTURAL CONTOUR ON THE PROJECTIONS TO PRODUCE AT THE WORKING PLANE A VERTICAL STRIKING ACTION COMBINED WITH A LATERALLY FRICTIONAL MOTION SUBSTANTIALLY IN THE WORKING PLANE TO STRIKE THE WASTE MATERIAL PORTIONS AND THEREAFTER FRICTIONALLY TEAR THEM LATERALLY IN THE PLANE OF THE SHEETS, SAID PROJECTIONS BEING SPACED WITH RESPECT TO THE CYCLICALLY PRESENTING MEANS SO THAT EACH TOOTH SEQUENTIALLY ENGAGES A WASTE PORTION ON A SUCCESSIVE ONE OF THE SHEETS IN SAID STACK, AND GUIDE MEANS ON THE TOOL SHAPED FOR POSITIONING THE PROJECTIONS AT A POSITION RELATIVE TO THE EDGES OF THE SHEETS IN THE STACK AND DIRECTING THE FLOW OF SEPARATED WASTE PORTIONS ALONG A DEFINED PATH. 